1. Field of the Invention
The present invention relates to electrical jack connectors, and particularly to modular jack connectors which can withstand high voltage shocks caused by events such as lightning strikes.
2. Description of the Prior Art
Modular jacks frequently comprise RJ-45 connectors for network data transmission and RJ-11 connectors for telephone signal transmission. Jack connectors are typically positioned proximate an edge portion of a circuit board, for mating with complementary modular plugs. Referring to FIG. 1, a conventional jack connector assembly 8 comprises an insulative housing 80 and receiving portions 81, 82 defined therein to receive RJ-45 and RJ-11 plugs respectively. First and second contact inserts 83, 84 are mounted in the receiving portions 81, 82 from a rear of the insulative housing. The first and second inserts 83, 84 have similar structure. The first insert 83 has four contacts 830, and the second insert 84 has eight contacts. Each contact 830 has a contact portion 833 for electrically engaging with an RJ-11 plug for telephone signal transmission. A bent portion 832 is exposed in an upper, rear part of the insulative housing 80, and is spaced about 0.3 mm from an outer shield 85 that surrounds the insulative housing 80 (as shown in FIG. 2).
Because the RJ-11 connector is used in a telephone network, it is susceptible to lightning strikes occurring on an associated telephone line. When this happens, the resultant very high voltage of, say, 1500 volts may cause electrical current to jump across the 0.3 mm gap from the outer shielding 85 to the bent portions 832 of the contacts 830. If so, the current surge enters the circuit board through the tail portions 831 of the contacts 830, frequently resulting in damage to electrical circuitry and components on the circuit board.
The abovementioned problem could be solved simply by increasing the size of the gap. However, such solution would not be practicable because it goes against the modem trend toward miniaturization of electronic devices.
Thus a compact RJ-45 modular jack connector which resists voltage surges is desired.
An object of the present invention to provide a modular jack assembly including juxtaposed RJ-11 and RJ-45 modular jacks, in which the RJ11 modular jack is compact yet still withstands high voltages caused by lightning strikes on associated telephone networks.
To achieve the above object, a modular jack connector assembly of the present invention comprises an insulative housing, first and second contact inserts, and a conductive outer shield. The housing defines first and second receiving spaces, for respectively receiving an RJ-11 and an RJ-45 modular plug therein. The contact inserts are mounted in the housing. One contact insert has four contacts for engaging with the RJ-11 modular plug, while the other contact insert has eight contacts for engaging with the RJ-45 modular plug. A shield encloses the housing to protect the contacts from electromagnetic interference. Each RJ-11 modular plug engaging contact has an upper, rear bent portion which is neither covered by the housing nor embedded in the insert. The shield defines an opening therein. The opening is disposed above the upper, rear bent portions of the RJ-11 modular plug engaging contacts, such that a substantial gap exists between the shield and the bent portions. Thus when high voltage is applied to the shield as a result of a lightning strike on an associated telephone line, current cannot jump from the shield to the bent portions of the contacts. Therefore no damage is sustained to electrical circuitry or components on a circuit board on which the modular jack assembly is mounted.